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Title: Triple-{alpha} reaction rate constrained by stellar evolution models

Abstract

We investigate the quantitative constraint on the triple-{alpha} reaction rate based on stellar evolution theory, motivated by the recent significant revision of the rate proposed by nuclear physics calculations. Targeted stellar models were computed in order to investigate the impact of that rate in the mass range of 0.8{<=}M/M{sub Circled-Dot-Operator }{<=}25 and in the metallicity range between Z= 0 and Z= 0.02. The revised rate has a significant impact on the evolution of low-and intermediate-mass stars, while its influence on the evolution of massive stars (M > 10M{sub Circled-Dot-Operator }) is minimal. We find that employing the revised rate suppresses helium shell flashes on AGB phase for stars in the initial mass range 0.8{<=}M/M{sub Circled-Dot-Operator }{<=}6, which is contradictory to what is observed. The absence of helium shell flashes is due to the weak temperature dependence of the revised triple-{alpha} reaction cross section at the temperature involved. In our models, it is suggested that the temperature dependence of the cross section should have at least {nu} > 10 at T = 1-1.2 Multiplication-Sign 10{sup 8}K where the cross section is proportional to T{sup {nu}}. We also derive the helium ignition curve to estimate the maximum cross section to retain themore » low-mass first red giants. The semi-analytically derived ignition curves suggest that the reaction rate should be less than {approx} 10{sup -29} cm{sup 6} s{sup -1} mole{sup -2} at Almost-Equal-To 10{sup 7.8} K, which corresponds to about three orders of magnitude larger than that of the NACRE compilation.« less

Authors:
; ;  [1];  [2];  [3]
  1. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)
  2. (United Kingdom) and Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8583 (Japan)
  3. (Japan)
Publication Date:
OSTI Identifier:
22075754
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 1484; Journal Issue: 1; Conference: Conference on origin of matter and evolution of galaxies 2011, Wako (Japan), 14-17 Nov 2011; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALPHA PARTICLES; ASTROPHYSICS; CROSS SECTIONS; GIANT STARS; HELIUM 4 TARGET; NUCLEAR REACTION KINETICS; STAR EVOLUTION; TEMPERATURE DEPENDENCE; THERMONUCLEAR IGNITION; THERMONUCLEAR REACTIONS

Citation Formats

Suda, Takuma, Hirschi, Raphael, Fujimoto, Masayuki Y., Keele University, Keele, Staffordshire ST5 5BG, and Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810. Triple-{alpha} reaction rate constrained by stellar evolution models. United States: N. p., 2012. Web. doi:10.1063/1.4763405.
Suda, Takuma, Hirschi, Raphael, Fujimoto, Masayuki Y., Keele University, Keele, Staffordshire ST5 5BG, & Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810. Triple-{alpha} reaction rate constrained by stellar evolution models. United States. doi:10.1063/1.4763405.
Suda, Takuma, Hirschi, Raphael, Fujimoto, Masayuki Y., Keele University, Keele, Staffordshire ST5 5BG, and Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810. Mon . "Triple-{alpha} reaction rate constrained by stellar evolution models". United States. doi:10.1063/1.4763405.
@article{osti_22075754,
title = {Triple-{alpha} reaction rate constrained by stellar evolution models},
author = {Suda, Takuma and Hirschi, Raphael and Fujimoto, Masayuki Y. and Keele University, Keele, Staffordshire ST5 5BG and Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810},
abstractNote = {We investigate the quantitative constraint on the triple-{alpha} reaction rate based on stellar evolution theory, motivated by the recent significant revision of the rate proposed by nuclear physics calculations. Targeted stellar models were computed in order to investigate the impact of that rate in the mass range of 0.8{<=}M/M{sub Circled-Dot-Operator }{<=}25 and in the metallicity range between Z= 0 and Z= 0.02. The revised rate has a significant impact on the evolution of low-and intermediate-mass stars, while its influence on the evolution of massive stars (M > 10M{sub Circled-Dot-Operator }) is minimal. We find that employing the revised rate suppresses helium shell flashes on AGB phase for stars in the initial mass range 0.8{<=}M/M{sub Circled-Dot-Operator }{<=}6, which is contradictory to what is observed. The absence of helium shell flashes is due to the weak temperature dependence of the revised triple-{alpha} reaction cross section at the temperature involved. In our models, it is suggested that the temperature dependence of the cross section should have at least {nu} > 10 at T = 1-1.2 Multiplication-Sign 10{sup 8}K where the cross section is proportional to T{sup {nu}}. We also derive the helium ignition curve to estimate the maximum cross section to retain the low-mass first red giants. The semi-analytically derived ignition curves suggest that the reaction rate should be less than {approx} 10{sup -29} cm{sup 6} s{sup -1} mole{sup -2} at Almost-Equal-To 10{sup 7.8} K, which corresponds to about three orders of magnitude larger than that of the NACRE compilation.},
doi = {10.1063/1.4763405},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 1484,
place = {United States},
year = {2012},
month = {11}
}